The present invention relates in general to shields used to prevent air-borne particles from contaminating the environment within the shield. More particularly, the invention relates to clean environment enclosures typically employed in paint operations in manufacturing plants.
In manufacturing facilities where products are painted, it is necessary that the environment immediately surrounding the paint operation be as free as possible from dust, dirt and other air-borne contaminants in order to provide the best application of paint to the product.
Various forms of enclosures have been used to prevent air-borne contaminants from interfering with the paint application process. Such contaminant shields or "clean environment enclosures" are typically provided with positive airflow into the enclosure to prevent dust and dirt from entering the open ends of the enclosure. They are built of rigid side and top panels with opposed ends, with an attached flexible sheet(s) covering the periphery.
Two examples of prior art contaminant shields are disclosed in U.S. Pat. Nos. 4,769,962 and 4,860,778. These enclosures are relatively expensive to manufacture and require relatively lengthy installation time. For example, with each of these prior art shields flexible sheets are attached to individual panels in a relatively complicated manner, using a "tongue-in-groove" system, with clamps also being employed for further support.
It would therefore be desirable to provide a controlled environment enclosure which can be more easily and inexpensively constructed, quickly altered in structure for different applications and easily repaired.